The Active Denial System (ADS) is a non-lethal, directed-energy weapon developed by the U.S. military. It is a strong millimeter-wave transmitter primarily used for crowd control (the “goodbye effect”). Some ADS systems such as HPEM ADS are also used to disable vehicles.[3] Informally, the weapon is also called pain ray.

The main idea is basically a microwave mounted on top of a Humvee. If you express yourself against the establishment, they will issue you “burn waves”.